JPH11188643A - Cup type grinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cup type grinder which is excellent in initial conformability and truing characteristics. SOLUTION: This cup type grinder is provided with a cup type metal base 2, and a number of abrasive grain layer segments 6 arranged at the lower end surface 4 of the metal base 2 in an annular shape. The grinder outer periphery side and inner periphery side of the abrasive grain layer segment 6 are chamfered to form an inclined surface. To supply grinding fluid to the metal base 2 from the inside of the abrasive grain layer segment 6, a fluid receiving recessed part 14 and a number of fluid feeding hole 16 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cup-type grindstone used for various types of surface grinding.

[0002]

2. Description of the Related Art A general cup-shaped grindstone is formed by fixing a large number of curved rectangular parallelepiped abrasive grain layer segments on one end surface of a cup-shaped base along a circumference centered on the base metal axis. And is used for various types of surface grinding.

[0003] Among these types of surface grinding, the one requiring particularly high planarity is wafer surface grinding. In general surface grinding of a wafer, as shown in FIGS. 6 and 7, one annular groove is formed on one end surface of a cup-shaped base 23, and a curved rectangular parallelepiped abrasive layer is formed in the groove. A cup-shaped grindstone 22 in which many segments 24 are fitted and fixed is used. Then, the wafer W is coaxially fixed on the lower platen 21 of the grinding device, and while rotating the lower platen 21 around the axis,
The cup-shaped grindstone 22 fixed to the upper stool is rotated while being eccentric from the center of the lower stool 21, and the abrasive layer segment 2 is rotated.
4 in parallel with the upper surface of the wafer W,
The upper surface of the wafer W is ground.

[0004]

By the way, in the prior art, an arc-shaped streak mark or the like is likely to be formed on a wafer immediately after surface grinding is started using a new cup-shaped grindstone. Can not meet
There is a problem that it is necessary to perform break-in grinding for a relatively long time, and so-called initial familiarity is poor. Since the break-in grinding requires a long time as described above, the wafer manufacturing process is interrupted for a long time every time the cup-shaped grindstone is replaced, which has been a factor that impedes productivity.

When a new cup grindstone is used, the lower end face of the abrasive grain layer segment needs to be slightly ground with a truing grindstone to correct the shape (truing). The mold grindstone has problems that not only takes a long time due to a relatively large amount of grinding, but also that chipping easily occurs in the abrasive grain layer segment. The same problems as the above-mentioned problems can be said to a greater or lesser extent in surface grinding of a work material other than a wafer.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cup-type grindstone having good initial familiarity and excellent truing characteristics.

[0007]

In order to solve the above-mentioned problems, a cup-type grindstone according to the present invention comprises:
A plurality of abrasive grains arranged in a ring are provided on the lower end surface of the base metal, and the edges of the abrasive grains on the inner peripheral side and the outer peripheral side of the grindstone are chamfered.

Since the inner and outer edges of the grindstone of the abrasive grains are chamfered, the edges of the abrasive grains form streak marks on the work material even when a new cup-shaped grindstone is used. It is difficult to have good initial familiarity. In addition, truing can be performed promptly by reducing the end surface area of the abrasive grains, and trouble such as chipping of the abrasive grains caused by contact with the truing grindstone can be prevented.

[0009]

1 and 2 are a bottom view and a vertical sectional view, respectively, showing a first embodiment of a cup-type grindstone according to the present invention. An annular groove 8 is formed on the lower end face 4 coaxially with the base metal 2, and a plurality of abrasive grain layer segments (abrasive grains) 6 are fitted in a line at equal intervals and fixed in the groove 8. Things.
Note that “up and down” used in this description does not limit the usage mode of the cup-type grindstone 1.

The base metal 2 has an annular shape having a center hole 10, and a shallow concave portion 1 is formed on the inner peripheral side of the lower end surface over the entire circumference.
8 are formed. A groove 8 having a U-shaped cross section is formed along a true circle coaxial with the base metal 2 on the lower end surface 4 which is annular and has a constant width and located on the outer peripheral side of the concave portion 18. The upper end of the segment 6 is fitted and fixed by well-known fixing means such as brazing.

The main feature of this embodiment is that the outer peripheral edge and the inner peripheral edge of the lower end face of these abrasive grain layer segments 6 are:
As shown in FIG. 3, each beveled over a certain width,
That is, flat inclined surfaces 6b and 6c are formed.
A horizontal surface 6a having a fixed width is left over the entire length of the abrasive grain layer segment 6 between the inclined surfaces 6b and 6c, and the workpiece can be ground by the horizontal surface 6a.

Although the inclination angle α of the outer peripheral side inclined surface 6b with respect to the horizontal plane 6a is not limited, it is generally preferably 1 to 20 °, and more preferably 3 to 15 °. If the inclination angle is too small or too large, the effect of improving the initial familiarity is reduced in any case.

Although the inclination angle β of the inner peripheral side inclined surface 6c with respect to the horizontal plane 6a is not limited, it is generally preferably 1 to 20 °, more preferably 3 to 15 °. If the inclination angle is too small or too large, the effect of improving the initial familiarity is reduced in any case.

Although the width T1 of the horizontal surface 6a is not limited, it is 30 to 30 times the total width (T1 + T2 + T3) of the abrasive grain layer segment 6.
It is preferably 80%, more preferably 33 to
50%. If it is larger than the above range, the effect of improving the initial conformability decreases, and if the width T1 of the abrasive grain layer segment 6 is smaller than the above range, the grinding characteristics are largely changed, which is not preferable.

The ratio T2: T3 of the widths T2, T3 of the inclined surfaces 6b, 6c is not limited, but is preferably 1: 1 to 3: 1, more preferably 1.2: 1 to 2: 1. is there. Since the work material enters from the outer peripheral side to the inner peripheral side of the abrasive grain layer segment 6, if T2 is relatively increased, the adaptability at the time of truing can be improved, and furthermore, damage to the work material Can be reduced.

The dimensions of the base metal 2 and the abrasive grain layer segment 6 are not limited, but the width of the abrasive grain layer segment 6 is preferably 1.5 to 6 mm, and more preferably 2 to 5 mm, particularly when a preferable value is shown for wafer grinding. It is. Abrasive layer segment 6
The length of the wafer is not limited.
About 0 to 40 mm is preferable. Further, the circumferential gap between the abrasive grain layer segments 6 is not limited, but is preferably about 1 to 3 mm for wafer grinding. Within such a range, the wafer can be accurately and efficiently ground.

The upper end surface of the base metal 2 is formed with a liquid-receiving concave portion 14 which is coaxial with the base metal axis. The liquid receiving concave portion 14 has a substantially U-shaped cross section having an outer peripheral side surface 14a, an inner bottom surface 14b, and an inner peripheral side surface 14c, and the outer peripheral side surface 14a is an inclined surface extending radially outward from above to below. The bottom surface 14b is a horizontal surface, and the inner peripheral side surface 14c is a vertical surface.

When the outer peripheral side surface 14a is inclined as described above, the grinding fluid supplied into the liquid receiving recess 14 is propelled downward along the outer peripheral side surface 14a by the centrifugal force of the grinding wheel rotation.
A pressure toward the outer peripheral bottom surface of the liquid receiving recess 14 is generated. Therefore, it is possible to prevent the grinding liquid from overflowing from the liquid receiving recess 14 and spilling out. The angle formed by the outer peripheral side surface 14a and the grinding wheel axis is not limited, but is preferably 10 to 45 °, and more preferably 20 to 40 °. If this angle is too large, it is difficult to secure the opening width of the liquid receiving concave portion 14, and if it is too small, the grinding fluid supplied into the liquid receiving concave portion 14 jumps out of the liquid receiving concave portion 14 due to the centrifugal force of the grinding wheel rotation. It is easier.

In this embodiment, the inner bottom surface 14b is formed as a horizontal surface. However, if necessary, the inner bottom surface 14b may be formed as an inclined surface which is inclined downward toward the outside in the grinding wheel radial direction. With such an inclination, the grinding fluid supplied into the liquid receiving recess 14 is propelled toward the outer periphery along the inner bottom surface 14b by gravity,
Since pressure is generated toward the bottom surface on the outer peripheral side of the liquid receiving concave portion 14,
It flows into the liquid supply hole 16 at a higher pressure.

The base metal 2 is provided on the inner bottom surface 14b of the liquid receiving recess 14.
A large number of liquid supply holes 16 are formed at regular intervals in the circumferential direction, and the lower ends of these liquid supply holes 16 are opened at locations located on the inner peripheral side of the abrasive grain layer segment 6 as shown in FIG. I have.
The liquid supply holes 16 are formed at an angle that spreads outward in the base metal radial direction as going downward from above.
The angle between the axis of and the wheel axis is not limited,
It is preferably 30 °, more preferably 10 °
20 °. Within such a range, acceleration of the grinding fluid by centrifugal force is appropriate, and formation of the fluid supply hole 16 is also easy.

At the same time as the liquid supply hole 16 is inclined outward, the liquid supply hole 16 may be inclined in a direction having a helical angle in a direction opposite to the direction of rotation of the grindstone as going from above to below. This is because, when the cup-shaped grindstone 1 has such a spiral angle, a downward thrust is generated in the grinding fluid in the fluid supply hole 16 due to the rotation of the cup-shaped grindstone 1, and the pressure at which the grinding fluid is jetted increases.

The number and opening diameter of the liquid supply holes 16 are not limited, but an appropriate diameter and number are set so that the grinding liquid can be uniformly supplied over the entire circumference of the base metal 2 and the strength of the base metal 2 is not impaired. Should be selected. Generally, the opening diameter of the lower end of the liquid supply hole 16 is preferably about 2 to 4 mm, and the arrangement pitch of the liquid supply holes 16 in the circumferential direction of the grindstone is preferably about 7 to 15 mm.

On the upper surface of the base metal 2, a plurality of mounting holes 12 are formed at intervals in the circumferential direction on the inner peripheral side of the liquid receiving recess 14, and are not shown through these mounting holes 12. It can be attached to the upper surface plate of the grinding device.
The liquid receiving concave portion 14 is formed at a position not closed by the upper platen. However, the mounting structure of the base 2 is not limited in the present invention. For example, a structure in which the base 2 is sandwiched between flanges without forming the mounting holes 12 may be used.

The abrasive grain layer segment 6 may be formed of any conventionally used material, and is selected according to the work material. That is, diamond or CBN
Or a metal-bonded abrasive layer in which general abrasive grains such as SiC or Al ₂ O ₃ are solidified with a metal binder, or a resin-bonded abrasive in which the abrasive grains are solidified with various resin binders. It may be a grain layer, a vitrified bond abrasive grain layer in which the abrasive grains are solidified with a glass binder or the like, or an electrodeposition abrasive grain layer in which the abrasive grains are fixed with an electrodeposited metal, or an electroformed It may be an abrasive layer. In particular, when used for wafer grinding, the abrasive layer segment 6 is preferably a resin-bonded abrasive layer. The abrasive layer segment 6 may be directly brazed to the end face 4 without forming the groove 8.

In order to use the cup-shaped grindstone 1 having the above structure, the cup-shaped grindstone 1 is fixed to a surface plate or a spindle of a grinding device and rotated, and the grinding fluid is continuously supplied to the liquid receiving recess 14. Then, the horizontal surface 6a of the abrasive grain layer segment 6 is applied to the work material and ground. The grinding liquid supplied to the liquid receiving recess 14 is jetted downward from the liquid supply hole 16 by centrifugal force and gravity, and is supplied to a contact point (grinding portion) between the abrasive grain layer segment 6 and the work material or in the vicinity thereof. You. During the repetition of the grinding, the horizontal surface 6a gradually wears and the inclined surface 6a
Although b and 6c become smaller, the effect of the present invention can be achieved.

According to the cup-type grindstone 1, since the inclined surfaces 6b and 6c are previously formed at the lower end of the abrasive grain layer segment 6, even when the cup-type grindstone 1 is used in a new state, the abrasive grains are not removed. Streak marks are less likely to be formed on the work material due to the edges of the layer segments 6, and the initial familiarity is good.
Therefore, it is possible to reduce the time required for the break-in grinding, and it is possible to improve the productivity of wafers and the like accordingly.

Further, since the area of the horizontal surface 6a of the abrasive grain layer segment 6 is small, truing can be performed promptly before the start of grinding, and the truing characteristics are good. Problems such as chipping can be prevented.

Further, since the inclined surface 6c is formed on the inner peripheral side of the abrasive grain layer segment 6, the grinding fluid ejected from the liquid supply hole 16 can enter the interface between the horizontal surface 6a and the work material. This facilitates the removal of chips that easily accumulate at the interface, so that it is possible to maintain good sharpness over a long period of time.

[Second Embodiment] FIG. 4 is a bottom view showing a second embodiment of the present invention. In the first embodiment, the abrasive grain layer segments 6 are arranged along a perfect circle. However, the second embodiment has a new feature that the abrasive grain layer segments 6 are arranged along an ellipse. . Other configurations are the first
It may be the same as the embodiment. Although the difference between the major axis and the minor axis of the ellipse is not limited, the width of the abrasive grain layer segment 5 is 5-10.
0%, more preferably 10 to 6%.
0%.

By arranging the abrasive grain layer segments 6 along an ellipse, in this embodiment, since the abrasive grain layer segments 6 oscillate to the inner peripheral side and the outer peripheral side, the work material is cut. The occurrence of traces can be further prevented. Further, in the present invention, since the inner and outer edges of the abrasive grain layer segment 6 are chamfered, in the process of shaving the work material while swinging to the inner and outer peripheral sides, the surface of the work material is physically This is particularly effective because there is no problem of causing damage.

Instead of arranging the abrasive grain layer segments 6 in an elliptical shape, the abrasive grain layer segments 6 are arranged along a distorted circumference such as a trochoid curve, a cycloid curve, or a sin curve having the circumference as the center of amplitude. Can also be arranged. Compared to the case of arranging along a 180 ° rotationally symmetric ellipse as in the second embodiment, 120 ° rotationally symmetric or 9 ° rotationally symmetric.
A rotation symmetry of 0 ° facilitates better rotation balance.

[Third Embodiment] FIG. 5 shows a third embodiment according to the present invention.
3 shows a cross-sectional shape of an abrasive grain layer segment 6 in the embodiment. In the first embodiment, the inclined surfaces 6b and 6c are formed on the outer and inner peripheral edges of the abrasive grain layer segment 6, however, in the third embodiment, it is chamfered into a convex curved surface. Features. Of course, it is also possible to chamfer one plane and the other curved.

Although the three embodiments have been described above, the present invention is not limited to these embodiments, and the configurations of the embodiments may be appropriately combined, or may be applied to a conventional cup-type grindstone. It is also possible to combine other configurations employed.

[0034]

As described above, according to the cup-type grindstone according to the present invention, a new cup-type grindstone is used because the inner and outer edges of the abrasive grains are chamfered. Also in this case, the edge of the abrasive portion hardly causes streak marks on the work material, and the initial familiarity is good. In addition, since the end surface area of the abrasive portion is reduced, not only truing can be performed quickly, but also trouble such as generation of chipping in the abrasive portion due to contact with the truing grindstone can be prevented.

[Brief description of the drawings]

FIG. 1 is a bottom view of a first embodiment of a cup-type grindstone according to the present invention.

FIG. 2 is a longitudinal sectional view showing a part of the first embodiment.

FIG. 3 is a longitudinal sectional view of the abrasive grain layer segment of the first embodiment.

FIG. 4 is a bottom view showing a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of an abrasive grain layer segment according to a third embodiment of the present invention.

FIG. 6 is a front view showing a usage mode of a conventional cup-type grindstone.

FIG. 7 is a plan view showing a usage mode of a conventional cup-type grindstone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cup-type grindstone 2 Base metal 4 End surface 6 Abrasive layer segment (abrasive part) 6a Horizontal surface 6b, 6c Inclined surface 8 Groove 10 Center hole 12 Mounting hole 14 Liquid receiving recess 16 Liquid supply hole

Claims (5)

[Claims] 1. A metal mold comprising a cup-shaped base metal, and a large number of abrasive grains arranged annularly on the lower end surface of the base metal. A cup-shaped whetstone characterized by being chamfered. 2. The cup-type grindstone according to claim 1, wherein said abrasive grains are arranged along a distorted circumference. 3. The cup-type grindstone according to claim 1, wherein the abrasive grains are arranged along an ellipse. 4. The abrasive grain portion is an abrasive grain layer segment having a curved rectangular parallelepiped shape, and each edge of the abrasive grain layer segment on the inner peripheral side and the outer peripheral side of the grindstone is provided at the lower end face of the abrasive grain layer segment. The cup-shaped grindstone according to any one of claims 1 to 3, wherein inclined surfaces each forming 1 to 20 ° are formed. 5. A liquid receiving recess is formed on an upper end surface of the base metal, and one end is opened in an inner bottom surface of the liquid receiving recess and the other end is a lower surface of the base metal inside the base metal. The cup-type grindstone according to any one of claims 1 to 4, wherein at least one liquid supply hole that opens at a position on the inner peripheral side of the abrasive grain portion is formed.